In energy harvesting (or, according to other designations, power harvesting or energy scavenging), energy from sources such as e.g. solar panels, wind generators, thermal generators of various types is stored for possible use in devices such as wireless portable devices or wireless sensors (e.g. in wireless sensor network—WSN—applications).
Nowadays, more and more emerging applications may be facilitated by the availability of battery-less systems based on different harvesting approaches (i.e., photo-voltaic, piezo, radio-frequency, etc.), with the purpose of implementing low-cost systems with highly integrated wireless platforms. Furthermore, battery-less systems may facilitate developments in all those scenarios where periodical node battery replacement may be impractical e.g. because of either a large number of nodes or inaccessible node placement (e.g., implanted medical devices, smart concrete systems, or in general devices located in hazardous environments). A growing demand thus exists for improved energy harvesting devices (energy harvesters).